The set of numbers {3, 5, x, 12, 15} is arranged in ascending order. If the median of this set is 10, what is the value of x?

✓ Correct Answer: Option B

For a set of 5 numbers arranged in ascending order, the median is the third number. Given the set {3, 5, x, 12, 15} is in ascending order and the median is 10, x must be 10, fitting between 5 and 12.